Anthropic and OpenAI launch lower-cost AI models amid competition from open-weight rivals

Anthropic and OpenAI on Tuesday each announced new, less costly artificial intelligence models as both frontier labs continue to face stiff competition from cheaper, open-weight competitors.

OpenAI introduced additional tiers to its GPT-6 family, with GPT-6 Sol and GPT-6 Luna, slashing the API prices by 50% compared with GPT-5.6 promotional pricing.

Sol, which is a tier below Astra, is meant for more complex workloads like coding, while the company's Luna offering is geared toward "high-volume tasks" like extracting information or summarizing documents, the company wrote.

Anthropic unveiled Claude Opus 5.5 on Tuesday, its latest release in the new Claude 5.5 model family. The company described the latest release as a more token-efficient version that will cost around 40% less to run than the company's Opus 5.

"One of the things we're continuing to innovate on is how to make that thinking, how to make the answering more efficient, so it uses less tokens depending on your effort setting," Dianne Penn, head of product management, research and labs at Anthropic, told CNBC in an interview.

The separate releases are the first to roll out since Anthropic CEO Dario Amodei called for an industry-wide slowdown on developing advanced AI as the debate about model safety reached a fever pitch in recent weeks.

Former Anthropic researcher Jacob Coxon set off the debate when he posted to X on Sept. 8 that he had quit his job, warning that both labs were "gambling with our lives."

OpenAI CEO Sam Altman and Tesla and SpaceX CEO Elon Musk also joined Amodei's call.

The new releases come as OpenAI and Anthropic work to satisfy customers who are looking for more cost-effective models and seeking to rein in AI spending.

The labs are facing pressure from companies that offer cheaper, open-weight models, like Chinese firms Alibaba, Moonshot AI and DeepSeek.

CNBC's Kate Rooney contributed to this report.